1. Field of the Invention
The present invention relates to respiratory interface devices, and, in particular, to a respiratory interface device, such as a mask, that includes a frame member and a cushion device, wherein the frame member and cushion device are coupled together using a clip assembly employing a plurality of tabs and corresponding detents.
2. Description of the Related Art
A variety of respiratory masks are known that cover the areas surrounding the nose and/or mouth of a human user and that are designed to create an effective fit against the user's face. Typically, air, gas, or a combination thereof can be provided at a positive pressure within the mask for consumption by the user. The uses for such masks include high altitude breathing (aviation applications), swimming, mining, fire fighting and various medical diagnostic and therapeutic applications.
One requisite of many of these masks, particularly medical respiratory masks, is that they provide a fit against the user's face that is effective to provide therapy or delivery of air and/or gas as mentioned herein and that the mask contours with the user's face to limit or prevent leakage of the air and/or gas being supplied. A known mask typically includes a faceplate constructed of a substantially rigid material selected from a variety of such materials known in the art, including, without limitation, polycarbonate, nylon and acrylonitrile butadiene styrene (ABS), and a cushion portion constructed of a substantially flexible material selected from a variety of such materials known in the art, including, without limitation, silicone.
The cushion portion is attached to the faceplate and the cushion portion functions to space the faceplate away from the user's face such that the soft cushion portion, and not the rigid faceplate, contacts the user's face to provide an effective fit. The space provided between the faceplate and the user's face forms a chamber for receiving gas from an external gas source for consumption by the user. It is important that the faceplate and cushion portion are connected using a mechanism that provides a tight seal such as to prevent leakage of the air and/or gas being supplied to the user.
Various mechanisms are known in the art to attach the faceplate and cushion portion. In one example, glue may be used to hold together the faceplate and cushion portion. The use of glue results in a mask wherein the cushion portion cannot be easily removed from the faceplate for cleaning. In another example, a tongue and groove assembly is used to connect a mask faceplate to a mask cushion portion. The faceplate can have a rim that includes an outwardly extending flange that engages with a corresponding rim on the cushion portion. The faceplate rim can further include a tongue which protrudes rearwardly from the back of the faceplate and is received in a corresponding complementary shaped groove or recess formed in rim of the cushion portion. A disadvantage of this type of tongue and groove assembly is that it can be complex to manufacture.